Valve shaft apparatus for use with rotary valves

ABSTRACT

An example valve shaft apparatus includes a shaft having a stationary seal and a dynamic seal spaced from the stationary seal. The stationary seal defines a first leakage detection area adjacent the stationary seal and the dynamic seal defines a second leakage detection area adjacent the dynamic seal. A seal leakage detector is integrally formed with the shaft to provide a visual indication of process fluid leakage within the first leakage detection area or within the second leakage detection area. The seal leakage detector has a passageway in fluid communication with the first leakage detection area and the second leakage detection area. The passageway has a cross-sectional profile that changes between the first and second leakage detection areas to prevent fluid from flowing from one of the leakage detection areas into a body of the fluid valve.

FIELD OF THE DISCLOSURE

This disclosure relates generally to fluid valves and, moreparticularly, to valve shaft apparatus for use with rotary valves.

BACKGROUND

Valves are commonly used in process control systems to control the flowof process fluids. Rotary valves (e.g., butterfly valves) typically havea closure member (e.g., a disc) disposed in a fluid path. A valve shaftoperatively couples the closure member to an actuator that rotates theclosure member between an open position and a closed position to allowor restrict fluid flow between an inlet and an outlet of the valve. Whenthe closure member is in the closed position, the closure membersealingly engages a valve seat or sealing surface (e.g., a seal ringfixed to the valve body) to restrict fluid flow through the valve.

A follower shaft (which may be integrally formed with the valve shaft)is typically coupled to an end of the closure member opposite the end ofthe valve shaft to provide support to the closure member so that theclosure member can maintain proper alignment with the sealing surfaceand provide a tight shut-off when the valve is in the closed position.Without a follower shaft, the closure member may deflect away from thesealing surface when the valve is in the closed position, therebycausing fluid leakage between the inlet and the outlet when the valve isin a closed position. Typically, a mechanical fastener (e.g., a pin, aweld, etc.) is employed to couple the follower shaft to the closuremember. The follower shaft rotates with the closure member as theclosure member moves between the first and second positions and an endcap retains the follower shaft within the valve body.

However, other than a welded connection, pins and/or other mechanicalfasteners do not provide a sanitary connection between the followershaft and the closure member, which can cause bacterial growth that cancontaminate the process fluid. In some applications such as, forexample, the food and beverage industry and the pharmaceutical industry,sanitary valves are often employed. Thus, sanitary valves typicallyinclude a follower shaft and a valve shaft that are coupled to theclosure member via welding. However, welding a follower shaft and/or thevalve shaft to the closure member requires the use of a split-body valvein order to enable assembly of the fluid valve. Split-body valvesinclude a body liner or body seal to provide a seal and, thus, increasemanufacturing complexity and costs.

SUMMARY

A shaft apparatus for use with rotary fluid valves described hereinincludes a shaft having a stationary seal and a dynamic seal spaced fromthe stationary seal. The stationary seal defines a first leakagedetection area adjacent the stationary seal and the dynamic seal definesa second leakage detection area adjacent the dynamic seal. A sealleakage detector is integrally formed with the shaft to provide a visualindication of process fluid leakage within the first leakage detectionarea or within the second leakage detection area. The seal leakagedetector has a passageway in fluid communication with the first leakagedetection area and the second leakage detection area. The passageway hasa cross-sectional profile that changes between the first and secondleakage detection areas to prevent fluid from flowing from one of theleakage detection areas into a body of the fluid valve.

In another example, a rotary fluid valve includes a closure memberdisposed within a fluid flow path of a valve body to control fluid flowbetween an inlet and an outlet. A shaft has a first seal disposed withinan opening of the valve body to prevent fluid leakage into the openingand a second seal disposed within a cavity of the closure member toprevent fluid leakage into the cavity. A first passageway integrallyformed with the shaft and fluidly couples the opening of the valve bodyadjacent the first seal to the atmosphere to provide an indication ofprocess fluid leakage into the opening adjacent the first seal. A secondpassageway integrally formed with the shaft and adjacent the firstpassageway, where the second passageway fluidly couples the cavity ofthe closure member adjacent the second seal to the atmosphere to providean indication of process fluid leakage into the cavity of the closuremember adjacent the second seal.

In yet in another example, a shaft apparatus for use with a rotary fluidvalve comprises a shaft removably coupled to the fluid valve. The shafthaving a stationary seal to prevent fluid leakage through a body of thefluid valve. The shaft also having a passageway integrally formed withthe shaft to receive a process fluid flowing through the fluid valve.The passageway has a first portion having a first cross-sectional areaand a second portion having a second cross-sectional area different thanthe first cross-sectional area to provide a pressure differential suchthat the process fluid within the passageway flows toward an opening ofthe passageway.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a known example fluid valve having a valve trimassembly coupled via mechanical fasteners.

FIG. 2A is a cross-sectional view of a portion of a fluid valveimplemented with an example valve shaft apparatus described herein.

FIG. 2B illustrates another cross-sectional view of the example valveshaft apparatus of FIG. 2A.

FIG. 3 illustrates another example valve shaft apparatus describedherein.

FIG. 4 illustrates an example bearing that may be used to implement theexample valve shaft apparatus described herein.

DETAILED DESCRIPTION

The example valve shaft apparatus described herein may be generallyapplied for use with rotary fluid valves of any size, type, and/orgeometry to provide support to a closure member (e.g., a disc) of arotary fluid valve. The example valve shaft apparatus described hereinare particularly advantageous for use in sanitary applications becausethe valve shaft apparatus significantly reduces the likelihood ofbacterial growth and, thus, contamination of a process fluid.Additionally, the example valve shaft apparatus includes a seal leakageindicator or detector (e.g., a visual indicator) to provide anindication of process fluid leakage past a seal of the valve shaftapparatus. Detecting fluid leakage in sanitary applications relativelyquickly significantly reduces the likelihood of bacterial growth and,thus, contamination of the process fluid. Thus, the seal leakageindicator described herein is advantageous for use in sanitaryapplications because seal failure may cause contamination of the processfluid if not detected relatively quickly. Additionally or alternatively,the example valve shaft apparatus described herein may include asampling port and/or an injection port integrally formed with a shaft ofthe valve shaft apparatus. The example sampling and/or injection portmay be used to inject fluid (e.g., a chemical) into the fluid flow pathof the fluid valve or may be used to sample fluid flowing within thefluid valve while the fluid valve is in-line.

Before describing the example valve shaft apparatus, a brief discussionof a known fluid valve 100 having a known valve shaft apparatus 102 isprovided in connection with FIG. 1. Referring to FIG. 1, the valve 100includes a valve body 104 that houses a valve trim 106. The valve body104 is generally cylindrical and has a central opening 108 that definesa fluid flow passageway between an inlet 110 and an outlet (opposite theinlet 110 but not shown). As shown, the valve trim 106 includes a valveshaft 112, a closure member 114 (e.g., a disc), and a follower shaft116. In some examples, the valve shaft 112 and the follower shaft 116may be of unitary or single piece construction. A second end 118 (e.g.,a splined end, a square end, etc.) of the valve shaft 112 operativelycouples the closure member 114 to an actuator (not shown).

The closure member 114 is disposed within the fluid flow passageway andhas a peripheral edge 120 that sealingly engages a valve seat or annularsealing surface 122 (e.g., a seal ring) disposed in the central opening108 to prevent fluid flow through the valve 100 when the valve 100 is ina closed position. A flange 124 is integrally formed with the valve body104 and couples the valve body 104 to an actuator (not shown) viafasteners. The flange 124 also houses a packing system 128 to preventleakage of process fluid to the environment.

The valve body 104 also has a first opening 130 and a second opening 132that are generally coaxially aligned and adapted to receive the valveshaft 112 and the follower shaft 116, respectively. Bearings 134 and 136are disposed in the respective openings 130 and 132 between the valvebody 104 and the valve shaft 112 and the follower shaft 116,respectively. The bearings 134 and 136 align the closure member 114along an axis 138 and bearing flanges 140 a and 140 b align (i.e.,center) the closure member 114 relative to the central opening 108 andthe valve body 104. The bearings 134 and 136 also aid the shafts 112 and116 in alignment and rotation and reduce friction between the respectiveshafts 112 and 116 and the valve body 104.

In operation, an actuator applies or exerts a torque to the valve shaft112 (e.g., via a lever) to drive (e.g., rotate) the closure member 114between an open position to allow fluid flow through the valve 100 and aclosed position to restrict or prevent fluid flow through the valve 100.The follower shaft 116 rotates with the closure member 114 as theclosure member 114 moves between the open and closed positions. When theclosure member 114 is in the closed position, the follower shaft 116provides support to the closure member 114 and prevents the closuremember 114 from moving or deflecting away from the sealing surface 122.Thus, without the follower shaft 116, the closure member 114 may deflectand not sealingly engage the annular sealing surface 122, therebycausing leakage of process fluid across the closure member 114 betweenthe inlet 108 and the outlet.

In this example, the valve shaft 112 and the follower shaft 116 arecoupled to the closure member 114 via pins 142 and 144, respectively.However, pin connections (or other fasteners) are typically not suitablefor use in sanitary applications because such connections are prone tobacterial growth, which can contaminate the process fluid. In sanitaryapplications, welded connections are often employed because weldedconnections are not prone to bacterial growth and, thus, providesanitary connections. As a result, in such applications, the followershaft 116 and/or the valve shaft 112 are typically welded to the closuremember 114.

However, welded connections between the follower shaft 116 and/or theclosure member 114 require the use of a split valve body. The valveshaft 112 and the follower shaft 116 are welded to the closure member114 and the assembly is disposed within a valve body via an opening orslotted area of the valve body. A body seal or liner is disposed withinthe split valve body to provide a seal to prevent ingress of contaminateinto the valve body and/or prevent egress or leakage of fluid to theenvironment through the opening or slotted area of the split valve body.Split body valves increase manufacturing complexity and costs. Further,welding the follower shaft 116 to the closure member 114 may limitaccessibility to the follower shaft 116 during maintenance or repair.Typically, the valve 100 must be taken off-line (e.g., the valve trim106 must be removed from the valve body) during maintenance of thefollower shaft 116.

FIG. 2A illustrates an example valve shaft apparatus 200 describedherein coupled to a rotary fluid valve 202. FIG. 2B illustrates anothercross-sectional view of the example valve shaft apparatus 200. Theexample valve shaft apparatus 200 may be used to implement rotary valvessuch as, for example, the rotary valve 100 of FIG. 1 and/or any othersuitable fluid valves or fluid flow control devices. In particular, thevalve shaft apparatus 200 may be used in sanitary applications becausethe valve shaft apparatus 200 provides detection or indication (e.g.,visual detection) of seal failure or fluid leakage. In sanitaryapplications, failure to detect seal failure or fluid leakage in fluidvalves may significantly increase the likelihood of bacterial growth,which can cause contamination of the process fluid.

Referring to FIGS. 2A and 2B, the fluid valve 202 includes a valve body204 having a central opening 206 that defines a fluid flow path 208between an inlet 210 and an outlet 212. A closure member 214 (e.g., adisc) is disposed within the fluid flow path 208 to control fluid flowbetween the inlet 210 and the outlet 212. The closure member 214includes a peripheral edge 216 that sealingly engages a valve seat orannular sealing surface 218 (e.g., a seal ring) disposed in the centralopening 206 to prevent fluid flow through the fluid valve 202 when thefluid valve 202 is in a closed position. Additionally, the closuremember 214 includes a first bore or cavity 220 aligned with and a secondbore or cavity 222 about an axis 224. In the illustrated example, theclosure member 214 is depicted as a disc. However, in other examples,the closure member 214 can be any suitable closure member 214 such as,for example, a ball valve and/or any other suitable flow controlmembers.

The valve body 204 includes a drive end opening 226 and a support end oroutboard opening 228 opposite the drive end opening 226. In thisexample, the drive end opening 226 and the outboard opening 228 aregenerally coaxially aligned with the respective first and secondcavities 220 and 222 of the closure member 214 when the closure member214 is coupled to the valve body 204. The drive end opening 226 of thevalve body 204 receives a drive shaft 230 and the outboard opening 228of the valve body 204 receives the valve shaft apparatus 200.

The drive shaft 230 is disposed within the first cavity 220 of theclosure member 214 and is coupled to the closure member 214 via a weld232. Thus, the drive shaft 230 and the closure member 214 provide awelded connection (e.g., a sanitary connection). A bearing or sealmember 234 may be disposed in the drive end opening 226 between thevalve body 204 and the drive shaft 230 to reduce friction between thedrive shaft 230 and the valve body 204 and/or facilitate rotation of thedrive shaft 230 relative to the drive end opening 226. Additionally,seals and/or a packing system may be provided to prevent leakage offluid to the environment along the drive shaft 230 and/or through thedrive end opening 226. An actuator (e.g., a pneumatic actuator, anelectric actuator, a hydraulic actuator, etc.) may be operativelycoupled to the closure member 214 via the drive shaft 230 to move theclosure member 214 relative to the sealing surface 218 to control fluidflow between the inlet 210 and the outlet 212.

As shown, the valve shaft apparatus 200 is disposed within the outboardopening 228 of the valve body 204 opposite the drive shaft 230 or anoutboard side 238 of the valve body 204. In this example, the valveshaft apparatus 200 includes a shaft or body 240 having a first portion242 and a second portion 244. When coupled to the valve body 204, thefirst portion 242 is disposed within the opening 228 of the valve body204 and the second portion 244 is disposed within the cavity 222 of theclosure member 214. The first portion 242 of the shaft 240 isdimensioned or sized to have a close tolerance fit relative to theopening 228 so that the opening 228 guides and/or aligns the valve shaftapparatus 200 relative to the closure member 214 and the valve body 204.Also, the second portion 244 of the shaft 240 is dimensioned or sized tohave a close tolerance fit relative to the cavity 222 of the closuremember 214 so that the closure member 214 can rotate about the shaft240. Thus, in the illustrated example, a mechanical fastener is notrequired to couple the shaft 240 and the closure member 214. The shaft240 also includes a flange or flanged portion 246 to couple the shaft240 to the valve body 204. In this example, the flange 246 is integrallyformed with the shaft 240 as a unitary structure and the flange receivesfasteners 248 to removably couple the shaft 240 to the valve body 204.Although not shown, in another example, the shaft 240 may include athreaded base portion that threadably couples to the opening 228 (e.g.,a threaded opening) of the valve body 204 and/or may be coupled to thevalve body 204 via any other suitable fastening mechanism(s).

The shaft 240 includes a first or stationary seal 250 (e.g., an O-ring,a lip seal, etc.) and a second or dynamic seal 252 (e.g., an O-ring, alip seal, etc.) spaced away from the stationary seal 250. The stationaryseal 250 is at least partially disposed in a groove 254 on the firstportion 242 of the shaft 240 and the dynamic seal 252 is at leastpartially disposed in a groove 256 on the second portion 244 of theshaft 240. The stationary seal 250 is disposed in the opening 228 of thevalve body 204 to prevent fluid leakage into the opening 228 of thevalve body 204. The dynamic seal 252 is disposed in the cavity 222 ofthe closure member 214 to prevent fluid leakage into the cavity 222 ofthe closure member 214. In one example, when the fluid valve 202 is usedfor non-sanitary applications, the dynamic seal 252 is not required andmay be removed from the shaft 240.

When the shaft 240 is coupled to the valve body 204, the stationary seal250 defines a first leakage detection area 258 adjacent the stationaryseal 250, and the dynamic seal 252 defines a second leakage detectionarea 260 adjacent the dynamic seal 252. The first leakage detection area258 can be defined between an outer surface 262 of the shaft 240 and aninner surface 264 of the opening 228 adjacent the stationary seal 250and the second leakage detection area 260 may be defined as a portion ofthe cavity 222 of the closure member 214 adjacent the dynamic seal 252.A bearing 266 is disposed adjacent an end 268 the shaft 240 within thecavity 222 to reduce friction and facilitate rotation of the closuremember 214 about the shaft 240. The end 268 of the second portion 244 ofthe shaft 240 may include a recess or reduced diameter portion 270 a andstepped or flanged portion 270 b to receive the bearing 266.

In this example, the valve shaft apparatus 200 also includes a sealleakage detector or indicator 272 (e.g., a visual indicator). The sealleakage detector 272 is integrally formed with the shaft 240 andprovides an indication if the seals 250 and/or 252 fail to provide asufficient seal (e.g., if the seals 250 and/or 252 have failed). Morespecifically, the seal leakage detector 272 provides an indication offluid leakage in the first leakage detection area 258 or opening 228adjacent the stationary seal 250 and/or fluid leakage within the secondleakage detection area 260 or cavity 222 adjacent the dynamic seal 252.As shown, the seal leakage detector 272 is depicted as a weep hole orpassageway 274. The passageway 274 fluidly couples the first leakagedetection area 258 to the atmosphere and the second leakage detectionarea 260 to the atmosphere via an opening 276 adjacent an outer surface278 of the flange 246 or the valve body 204.

As shown, the passageway 274 includes a first passageway 280 in fluidcommunication with the first leakage detection area 258 and theatmosphere and a second passageway 282 in fluid communication with thesecond leakage detection area 260 and the atmosphere. The passageway 274further includes a first channel or path 284 adjacent the stationaryseal 250 to fluidly couple the first leakage detection area 258 and thefirst passageway 280 and a second channel or path 286 adjacent thedynamic seal 252 to fluidly couple the second leakage detection area 260and the second passageway 282. In this example, the first and secondchannels 284 and 286 are bores or apertures having diameters ofapproximately 1 millimeter. However, in other examples, the first andsecond channels 284 and/or 286 can have any suitable shape,cross-sectional profile and/or dimensions.

Additionally, in this example, the shaft 240 includes a first annulargroove or channel 288 and a second annular channel or groove 290. Thefirst annular groove 288 is disposed along the first portion 242 of theshaft 240 adjacent the stationary seal 250 and is fluidly coupled to thefirst channel 284 to direct, guide or funnel fluid that may leak pastthe stationary seal 250 toward the first channel 284. Likewise, thesecond annular groove 290 is disposed along the second portion 244 ofthe shaft 240 adjacent the dynamic seal 252 and is fluidly coupled tothe second channel 286 to direct, guide or funnel fluid that may leakpast the dynamic seal 252 toward the second channel 286. The first andsecond grooves 288 and 290 facilitate or increase fluid flow toward therespective first and second channels 284 and 286 and/or to thepassageways 280 and 282. Such a configuration significantly increasesfluid leakage detection sensitivity, which is advantageous in sanitaryapplications because a delay in detecting seal leakage can causebacterial growth and contaminate the process fluid.

In this example, the first passageway 280 is coaxially aligned with thesecond passageway 282. Also, the first and second passageways 280 and282 are coaxially aligned with the axis 224. Generally, the passageway274 includes a profile (e.g., a cross-sectional profile) that changesbetween the first and second leakage detection areas 258 and 260 toprovide a pressure differential between the first and second passageways280 and 282 such that any fluid in the passageway 274 flows toward theopening 276 to prevent fluid from flowing from one of the leakagedetection areas 258 and 260 into the body 204 of the fluid valve 202 orcavity 222. For example, the passageway 274 may increase incross-sectional area along portions or sections of the shaft 240 betweenthe first and second leakage detection areas 258 and 260. In theillustrated example, the first passageway 280 has a firstcross-sectional area 292 a and the second passageway 282 has a secondcross-sectional area 292 b different than the first cross-sectional area292 a. In this example, the passageways 280 and 282 are cylindricallyshaped and the first cross-sectional area 292 a has a first diameterthat is greater than a second diameter of the second cross-sectionalarea 292 b. For example, the first diameter may be approximately 4millimeters and the second diameter may be approximately 2 millimeters.Thus, as shown, the first passageway 280 is adjacent the secondpassageway 282 to provide a stepped profile 292 c between the first andsecond passageways 280 and 282.

As described in greater detail below, because the profile orcross-sectional area of the passageway 274 increases or is larger towardthe opening 276 or atmospheric side of the valve body 204, fluid withinthe first passageway 280 and/or the second passageway 282 flows towardthe atmosphere or the opening 276 instead of flowing toward the firstand/or second leakage detection areas 258 and 260. Stated differently,the fluid in the passageway 274 does not pressure load within theleakage detection areas 250 and 252 behind the stationary seal 250and/or the dynamic seal 252 that provide a tight seal. Thus, thepassageway 274 prevents fluid in the passageway 274 from flowing betweenthe first leakage detection area 258 and the second leakage detectionarea 260.

In other examples, the profile or cross-sectional area of the passageway274 may continually or gradually increase in size between the first andsecond leakage detection areas 258 and 260. Alternatively, although notshown, the valve shaft apparatus 200 may include a first seal leakagedetector associated with detecting leakage within the first leakagedetection area 258 that is independent or adjacent a second seal leakagedetector associated with detecting leakage within the second leakagedetection area 260. The first seal leakage detector may include a firstprimary passageway to fluidly couple the first leakage detection area258 to the atmosphere and the second seal leakage detector may include asecond primary passageway to fluidly couple the second leakage detectionarea 260 to the atmosphere such that the first path is not in fluidcommunication with the second path. In other words, in this example, thefirst and second seal leakage detectors are not fluidly coupled to theatmosphere via a common fluid passage.

In operation, an actuator operatively coupled to the closure member 214via the drive shaft 230 moves the closure member 214 between a first oropen position to allow fluid flow through the fluid flow path 208 and asecond position or closed position to prevent or restrict fluid flowthrough the fluid flow path 208. The drive shaft 230 and the closuremember 214 rotate within the valve body 204 and the closure member 214rotates relative to the shaft 240. When the fluid valve 202 is in aclosed position, the peripheral edge 216 of the closure member 214sealingly engages the valve seat or sealing surface 218 (e.g., a sealring) disposed in the fluid flow path 208 to effect a seal and preventfluid flow through the fluid valve 202. When the closure member 214 isin the closed position, the valve shaft apparatus 200 provides supportto the closure member 214 and prevents the closure member 214 fromdeflecting or moving away from the sealing surface 218. In other words,the shaft 240 maintains alignment of the closure member 214 relative tothe sealing surface 218.

The stationary seal 250 prevents fluid leakage into the opening 228 ofthe valve body 204 and the dynamic seal 252 prevents fluid leakage intothe cavity 222 of the closure member 214. If the stationary seal 250and/or dynamic seal 252 fail to provide a sufficient seal, fluid thatleaks past the stationary seal 250 and/or the dynamic seal 252 will flowtoward the opening 276 of the passageway 274. Fluid in the passageway274 (e.g., the first and second channels 284 and 286 and/or the firstand second passageways 280 and 282) will flow toward the opening 276because the fluid pressure within the first passageway 280 is less thanthe fluid pressure within the second passageway 282 due to the firstcross-sectional area 292 a (i.e., an area of the first passageway 280)being larger than the second cross-sectional area 292 b (i.e., an areaof the second passageway 282), thereby providing a path of leastresistance toward the opening 276. Thus, the passageway 274 isconfigured to prevent a build-up of fluid pressure within the passageway274.

More specifically, if the stationary seal 250 fails to provide asufficient seal, fluid that leaks past the stationary seal 250 flowstoward the first leakage detection area 258. The first annular groove288 facilitates or directs the fluid toward the first channel 284, whichchannels or directs the fluid toward the first passageway 280 of thepassageway 274. Fluid in the first passageway 280 flows toward theopening 276 of the passageway 274 in fluid communication with theatmosphere (e.g., the outboard side 238 of the fluid valve 202). Thefluid in the first passageway 280 will not flow toward the secondleakage detection area 260 or the cavity 222 (via the second channel286) because the cross-sectional area 292 b of the second passageway 282is the smaller than the cross-sectional area 292 a of the firstpassageway 280, thus the pressure of any fluid entering or already inthe second passageway 282 will be greater than the fluid pressure in thefirst passageway 280. In other words, because the cross-sectional areaof the passageway 274 increases between the first and second passageways280 and 282, a path of least resistance is provided toward the opening276 in fluid communication with the atmosphere, thereby causing the flowof any leakage fluid toward the opening 276.

Similarly, if the dynamic seal 252 fails to provide a sufficient seal,process fluid may leak or flow past the dynamic seal 252 into the secondleakage detection area 260 or cavity 222. The second annular groove 290facilitates or directs the fluid toward the second channel 286, whichchannels or directs the fluid toward the second passageway 282. Fluid inthe second passageway 282 flows toward the opening 276 of the passageway274 in fluid communication with the atmosphere (e.g., the outboard sideof the valve) and will not flow toward the first channel 284 or thefirst leakage detection area 258 (via the first channel 284) becauseeach of the second passageway 282 and the first channel 284 has across-sectional area (e.g., a diameter) that is smaller or less than thecross-sectional area (e.g., a diameter) of the first passageway 280 asdescribed above. The opening 276 of the passageway 274 provides anindication (e.g., a visual indication) that the seals 250 and/or 252 arenot properly functioning when process fluid leaks to the atmosphere viathe passageway 274 and out of the opening 276. Such seal leakageindication is particularly advantageous in sanitary applications becauseprolonged delay in detecting fluid leakage caused by seal failure cancause the process fluid to become contaminated.

If either one of the stationary and/or dynamic seals 250 and 252 failsto provide a sufficient seal, the valve shaft apparatus 200 can beremoved from the valve body 204. Upon inspection and detection of fluidleakage via the opening 276, the valve may 202 be shut-down and thevalve shaft apparatus 200 may be serviced. Because the valve shaftapparatus 200 can be assembled prior to assembling it to the fluid valve202, the valve shaft apparatus 200 can be serviced while the valve body204 is in-line. For example, the shaft 240 may be removed from the valvebody 204 via the fasteners 248. The shaft 240, the seals 250 and 252,and/or the bearing 266 may be removed from the valve body 204 and/orrepaired or replaced. After the stationary seals 250, the dynamic seal252 and/or the bearing 266 are repaired or replaced, the valve shaftapparatus 200 may be coupled to the valve body 204.

FIG. 3 illustrates yet another example valve shaft apparatus 300described herein that may be used to implement a fluid valve 302 (e.g.,the fluid valve 202 of FIGS. 2A and 2B). Those components of the valveshaft apparatus 300 and the fluid valve 302 that are substantiallysimilar or identical to the components of the valve shaft apparatus 200and the fluid valve 202 described above and that have functionssubstantially similar or identical to the functions of those componentswill not be described in detail again below. Instead, the interestedreader is referred to the above corresponding descriptions.

As shown, the valve shaft apparatus 300 includes a shaft or body 304having the first seal or stationary seal 250 (e.g., an O-ring) disposedalong a first portion 306 of the shaft 304 and the second seal ordynamic seal 252 (e.g., an O-ring) disposed along a second portion 308of the shaft 304 spaced from the stationary seal 250. The stationaryseal 250 is disposed in the opening 228 of the valve body 204 and thedynamic seal 252 is disposed in the cavity 222 of the closure member214. The stationary seal 250 prevents fluid leakage into the opening 228of the valve body 204 and the dynamic seal 252 prevents fluid leakageinto the cavity 222 of the closure member 214.

The shaft 304 includes a weep hole or passageway 310 integrally formedwith the shaft 304. The passageway 310 includes a channel 312 in fluidcommunication (e.g., in direct fluid communication) with the fluid flowpath 208 of the fluid valve 302. The channel 312 fluidly couples theprocess fluid flowing between the inlet 210 and the outlet 212 of thefluid valve 300 to the passageway 310. As shown, the channel 312 isdisposed between the stationary seal 250 and the dynamic seal 252. Anopening 314 (e.g., a partial opening, an annular groove, etc.) may bedisposed on an outer surface 316 of the shaft 302 in fluid communicationwith the channel 312 to direct, guide or funnel fluid flow toward thechannel 312 and, thus, the passageway 310. The shaft 304 includes aflange 318 integrally formed with the shaft 304. The flange 318removably couples the shaft 304 to the fluid valve 300 via, for example,fasteners (not shown). An opening 320 of the passageway 310 may beformed in the flange 318 and the opening 320 of the passageway 310receives a pressure fitting 322 (e.g., a NPT fitting, a quick disconnectvalve, etc.). The fitting 322 may have an externally threaded body 324that threadably couples to threads 326 of the opening 320. Thus, thepassageway 310 fluidly couples the opening 320 and/or the fitting 322and the channel 312. The passageway 310 may have any suitable shape.

In operation, the passageway 310 provides a sampling port and/orinjection port 328. In a sampling application, a sampling apparatus suchas, for example, a reservoir, a container, piping etc. may be fluidlycoupled to the passageway 310 via the pressure fitting 322. Processfluid flowing through the fluid valve 300 is received or flows towardthe passageway 310. More specifically, the passageway 310 receives fluidflowing through the fluid flow path 208 via the channel 312. Thepressure of the process fluid causes the fluid to flow toward theopening 320 of the passageway 310. The sampling apparatus, fluidlycoupled to the passageway 310 via the pressure fitting 322, receives theprocess fluid via the passageway 310. When the sampling apparatus isremoved from the pressure fitting 322 (e.g., disconnected from thefitting 322), the pressure fitting 322 prevents further fluid flowthrough the passageway 310. For example, a shut-off valve may be coupledto the pressure fitting 322 to control the fluid flow out of thepassageway 310.

Alternatively, an injection apparatus such as, for example, a pump orpiping may be coupled to the pressure fitting 322. A fluid (e.g., aliquid, a gas, a chemical, etc.) may be injected into the process fluidor the fluid flow path 208 of the fluid valve 300 via the passageway310. When complete, the injection apparatus may be removed from thepressure fitting 322, which prevents further fluid flow through thepassageway 310. For example, a shut-off valve may be coupled to thepressure fitting 322 to control the fluid flow into of the passageway310.

Additionally, although not shown, a valve shaft apparatus may includeboth the seal leakage detector 272 and the sampling port/injection port328. In other words, a valve shaft apparatus may be implemented withboth the passageway 274 and the passageway 310 separate from thepassageway 274. For example, a first passageway (e.g., the passageway274) may be integrally formed with a shaft corresponding to the sealleakage detector 272 and a second passageway (e.g., the passageway 310)may be integrally formed with the shaft corresponding to the samplingpassageway/injection passageway 328 such that the first passageway isnot in fluid communication with the second passageway. Further, thefirst passageway may have a first opening (e.g., the opening 276)fluidly coupled to the atmosphere and the second passageway may have asecond opening (e.g., the opening 320) to receive a pressure fitting(e.g., the pressure fitting 322).

In yet another example, a shaft may include a first passageway fordetection of fluid leakage in a first leakage detection area (e.g., thefirst leakage detection area 258 of FIGS. 2A and 2B), a secondpassageway (not fluidly coupled to the first passageway) for detectionof fluid leakage in a second leakage detection area (e.g., the secondleakage detection area 260 of FIGS. 2A and 2B), and a third passageway(not fluidly coupled to either the first or second fluid passageways)for a sampling/injection port (e.g., the sampling port/injection port328). In such an example, a flange of a shaft may be implemented withthree openings, a first opening to fluidly couple the first passagewayto the atmosphere, a second opening to fluidly couple the secondpassageway to the atmosphere, and a third opening fluidly coupled to thethird passageway and configured to receive a pressure fitting.

FIG. 4 illustrates an example bearing 400 that may be used to implementthe example valve shaft apparatus 200 of FIGS. 2A and 2B and the examplevalve shaft apparatus 300 of FIG. 3. As shown, the bearing 400 isimplemented with the example valve shaft apparatus 300 of FIG. 3. In theillustrated example, the bearing includes a combination radial bearing402 and a thrust bearing 404. A cavity 406 of a closure member 408 maybe formed with a substantially flat surface or hole 410 to provide abearing landing 412. The thrust bearing 404 engages the bearing landing412 or the flat surface 410 formed in a cavity 406 of the closure member408 to provide thrust support in the axial direction along an axis 414when a thrust force is imparted to the valve shaft apparatus 300 by, forexample, an actuator. The radial bearing 402 provides radial alignmentabout the axis 414 and/or facilitates rotation of the closure member 408about the shaft 306. Thus, the thrust bearing 404 supports a loadimparted to the shaft 306 in a direction along the axis 414 and theradial bearing 402 supports a load imparted to the shaft 306 in a radialdirection about the axis 414. In yet another example, a portion 416 ofthe shaft 306 adjacent the dynamic seal 252 may include a tapered end orsurface that matably engages a tapered surface of the cavity 406. Thebearing 400 may also include a tapered opening to matably engage orreceive the end 416 of the shaft 306.

Although certain methods, apparatus and articles of manufacturing havebeen described herein, the scope of coverage of this patent is notlimited thereto. To the contrary, this patent covers all methods,apparatus and articles of manufacturing fairly falling within the scopeof the appended claims either literally or under the doctrine ofequivalents.

What is claimed is:
 1. An apparatus for use with a fluid valvecomprising: a shaft removably coupled to the fluid valve, the shafthaving a stationary seal to prevent fluid leakage through a body of thefluid valve and a dynamic seal spaced from the stationary seal, thestationary seal defining a first leakage detection area adjacent thestationary seal and the dynamic seal defining a second leakage detectionarea adjacent the dynamic seal when the shaft is coupled to the fluidvalve, the shaft further comprising a first annular groove along anouter surface of the shaft adjacent the stationary seal and in fluidcommunication with a first channel, and a second annular groove alongthe outer surface of the shaft adjacent the dynamic seal and in fluidcommunication with a second channel; and a passageway integrally formedwith the shaft to receive a process fluid flowing through the fluidvalve, the passageway having a first portion having a firstcross-sectional area and a second portion having a secondcross-sectional area different than the first cross-sectional area toprovide a pressure differential such that the process fluid within thepassageway flows toward an opening of the passageway, wherein thepassageway comprises a seal leakage detector having a first channeladjacent the stationary seal that fluidly couples the first leakagedetection area and the passageway and a second channel adjacent thedynamic seal that fluidly couples the second leakage detection area andthe passageway.
 2. An apparatus as defined in claim 1, furthercomprising a sampling port or an injection port in fluid communicationwith the process fluid flowing through the fluid valve.
 3. An apparatusas defined in claim 2, wherein the sampling port or the injection portcomprises a channel disposed between the stationary seal and a closuremember of the fluid valve such that the channel is in fluidcommunication with a fluid flow path of the fluid valve, and wherein thechannel fluidly couples the process fluid and a second passage, whereinthe second passage is different than the passageway.
 4. An apparatus asdefined in claim 1, further comprising a flange integrally formed withthe shaft to couple the shaft to the fluid valve.
 5. An apparatus asdefined in claim 4, wherein the opening of the passageway is adjacent anouter surface of the flange and in fluid communication with theatmosphere.
 6. An apparatus as defined in claim 1, further comprising apressure fitting coupled to the opening of the passageway.
 7. Anapparatus as defined in claim 1, wherein the first portion has a firstdiameter and the second portion has a second diameter smaller than thefirst diameter.
 8. An apparatus as defined in claim 1, furthercomprising a bearing adjacent an end of the shaft to be disposed withina cavity of a valve closure member when the shaft is coupled to a bodyof the fluid valve, wherein the closure member is to rotate about theshaft during operation of the fluid valve.
 9. An apparatus as defined inclaim 1, wherein the passageway comprises a first path integrally formedwith the shaft to fluidly couple an opening of the valve body adjacentthe stationary seal to atmospheric pressure to provide an indication ofprocess fluid leakage into the opening of the valve body adjacent thestationary seal.
 10. An apparatus as defined in claim 1, wherein thepassageway fluidly couples the first and second leakage detection areasto an outer surface of a flange of the shaft or an outer surface of abody of the fluid valve.
 11. An apparatus as defined in claim 1, whereinthe passageway is coaxially aligned with a longitudinal axis of theshaft.
 12. An apparatus as defined in claim 1, wherein the secondcross-sectional area is smaller than the first cross-sectional area. 13.An apparatus as defined in claim 3, wherein the second passage isparallel relative to the passageway.
 14. An apparatus for use with afluid valve comprising: a shaft removably coupled to the fluid valve,the shaft having a stationary seal to prevent fluid leakage through avalve body of the fluid valve and a dynamic seal spaced from thestationary seal; and a passageway integrally formed with the shaft toreceive a process fluid flowing through the fluid valve, the passagewayhaving a first portion having a first cross-sectional area and a secondportion having a second cross-sectional area different than the firstcross-sectional area to provide a pressure differential such that theprocess fluid within the passageway flows toward an opening of thepassageway, wherein the passageway comprises a seal leakage detector,and wherein the passageway further comprises a first path integrallyformed with the shaft to fluidly couple an opening of the valve bodyadjacent the stationary seal to the atmosphere to provide an indicationof process fluid leakage into the opening of the valve body adjacent thestationary seal and a second path integrally formed with the shaft andadjacent the first path to fluidly couple a cavity of a closure memberadjacent the dynamic seal to the atmosphere to provide an indication ofprocess fluid leakage into the cavity of the closure member adjacent thedynamic seal.
 15. An apparatus as defined in claim 14, wherein the firstpath is fluidly coupled and coaxially aligned with the second path. 16.An apparatus as defined in claim 14, further comprising a sampling portor an injection port in fluid communication with the process fluidflowing through the fluid valve.
 17. An apparatus as defined in claim16, wherein the sampling port or the injection port comprises a channeldisposed between the stationary seal and the closure member of the fluidvalve such that the channel is in fluid communication with a fluid flowpath of the fluid valve, and wherein the channel fluidly couples theprocess fluid and a second passage, wherein the second passage isdifferent than the passageway.
 18. An apparatus as defined in claim 14,further comprising a flange integrally formed with the shaft to couplethe shaft to the fluid valve.
 19. An apparatus as defined in claim 18,wherein an opening of the passageway is adjacent an outer surface of theflange and in fluid communication with the atmosphere.
 20. An apparatusas defined in claim 19, further comprising a pressure fitting coupled toan opening of the passageway.
 21. An apparatus as defined in claim 14,wherein the first portion has a first diameter and the second portionhas a second diameter smaller than the first diameter.
 22. An apparatusas defined in claim 14, further comprising a bearing adjacent an end ofthe shaft to be disposed within the cavity of the closure member whenthe shaft is coupled to the body of the fluid valve, wherein the closuremember is to rotate about the shaft during operation of the fluid valve.23. An apparatus as defined in claim 14, wherein the passagewaycomprises a first annular groove along an outer surface of the shaftadjacent the stationary seal and in fluid communication with the firstpath, and a second annular groove along an outer surface of the shaftadjacent the dynamic seal and in fluid communication with the secondpath.
 24. An apparatus as defined in claim 14, wherein the passageway iscoaxially aligned with a longitudinal axis of the shaft.
 25. Anapparatus as defined in claim 14, wherein the second cross-sectionalarea is smaller than the first cross-sectional area.